Help! DIY aerial amp upgrade problems
John Graham
better signal for OnDigital mux C and D. (Too much mosaic to make them viewable)
I live in Winnersh, Berks and the OnD people say I'm on the fringes and not
actually supported, and even although I get all the other muxes well enough for a
stable picture they won't offer a site visit (ariel upgrade for Ł40). I can't watch
any music channels (MTV or UK-PLAY) as they're on muxes C and D, and there's too
much mosaic or just a red dot.
So... I tried to upgrade myself, starting with a newer and better distribution
amplifier as the old one is a bit suspect.
Using the OnD signal strength indicator for measurement; I used to get 2.4 for
1,2,A,B and 1.8 for C,D.
My aerial setup is (as bought with the house) :-
An aerial pointing at Crystal Palace
A smaller aerial pointing at Hannington
These two seem to be combined and a single coax coming into the loft and going
into (and coming out of) an Antiference UP2301/W black box (not powered).
That then feeds into another Antiference box PU1240, with coax sockets in and out.
This is a mains powered unit so I think this must be the signal amplifier.
The output from the amp is fed into an old screw terminal splitter box (not
powered) and there are cables from that running to all of the rooms that have UHF
wall sockets. There is some corrosion around a couple of terminals and I suspect
some water damage. I switched my living room lead with the bedroom lead and my
signal strength improves significantly, aso too the bedroom picture deteriorates.
Time to replace this unit, besides, there are some rooms which have sockets and no
capacity at the splitter.
My theory was to replace the PU1240 and splitter with a combined 8 way distribution
amp, a Labgear MSA281, and after a mail order transaction this unit turns up. After
carefully reading the instructions and fitting coax plugs everywhere I install and
switch on.
Results...
I now get a signal strength of 3.5 (from 2.4) for 1,2,A,B but zero for C,D (was
1.8)!!! Also, the signal in the bedroom shows 'interference', most noticably on
Ch3. How come??
I backtracked by removing the MSA281, restoring the PU1240 amp and directing its
output straight at the living room (onDigital) box. This time I get best results
ever, almost flawless picture on MTV and UK-PLAY. Signal strength is 2.8 on 1,2,A,B
and 2.5 on C,D. I put on a "Y" connector so that I can feed the bedroom and living
room. No noticable digital signal deterioration and perfect analogue picture in the
bedroom.
I replaced the old PU1240 with the MSA281 again, in this one-in-one-out
configuration. Same problem, loss of mux C,D and analogue interference.
I called my mail order suppliers and asked if it might be a faulty unit? They sent
another but it's just the same. I'm stumped, does anyone have any clues as to whats
going on?
Can anyone explain what the UP2301/W is for?
I had thought that fitting a distribution amp was a reasonably simple DIY job..
should I just pay a professional to come in to sort this out?
John
Rob Collis
I think some of the problem is that both Crystal Palace and Hannington use
Channel 29 for Digital TV. Ch29 (CP) is MUX D I believe. If your 2 aerials
are joined, all hell will be breaking loose on this channel.
Regards
Rob Collis
John Graham <jo...@rave.co.uk> wrote in message
news:w_At3.4774$wC.118236@stones...
> I've been trying to upgrade my aerial distribution amplifier so that I can
get a
> better signal for OnDigital mux C and D. (Too much mosaic to make them
viewable)
>
> I live in Winnersh, Berks and the OnD people say I'm on the fringes and
not
> actually supported, and even although I get all the other muxes well
enough for a
> stable picture they won't offer a site visit (ariel upgrade for Ł40). I
can't watch
> any music channels (MTV or UK-PLAY) as they're on muxes C and D, and
there's too
> much mosaic or just a red dot.
>
> So... I tried to upgrade myself, starting with a newer and better
distribution
> amplifier as the old one is a bit suspect.
>
> Using the OnD signal strength indicator for measurement; I used to get 2.4
for
> 1,2,A,B and 1.8 for C,D.
>
> My aerial setup is (as bought with the house) :-
>
> An aerial pointing at Crystal Palace
> A smaller aerial pointing at Hannington
......
John Graham
>
>John,
>I think some of the problem is that both Crystal Palace and Hannington use
>Channel 29 for Digital TV. Ch29 (CP) is MUX D I believe. If your 2 aerials
>are joined, all hell will be breaking loose on this channel.
>
Thanks Rob,
I thought of that that too, except when I feed the directly from the old amp straight to
the OnD box I get perfect signal on mux C and D, and that feed is from the combined
aerials.
It's only when I introduce the distribution box that trouble happens.
John
Simon Clowes
The Antiference UP2301/W is a wideband (W) masthead amplifier. It is powered
by the Antiference box PU1240 which passes 12 volts up the coax cable to the
UP2301/W. I know this, as I have the same amplifier and power supply unit !
I too found analogue interference if I tried to add another amplifier. I
think the PU1240 puts 12 volts in both directions both up and down the coax,
and it is this 12 volts that interferes with the second amp.
The UP2301/W is one of the highest gain, easily available amplifiers
Maplins for example ), as it is about 24dB gain. The eight way amplifiers
tend to be only 3-4 dB gain for each connection. Most "off the shelf" amps
tend to be the same total gain, split over however many outputs the amp has.
The set up I have is that the UP2301/W and PU1240 amplify the signal to the
OND box, the aerial then feeds from the OND box to the video, and the video
output then feeds to a 3 way splitter, which feeds to different rooms in the
house. This enables viewing of OND and video in any room.
Hope this helps,
Simon.
John Graham wrote in message ...
>I've been trying to upgrade my aerial distribution amplifier so that I can
get a
>better signal for OnDigital mux C and D. (Too much mosaic to make them
viewable)
>
>I live in Winnersh, Berks and the OnD people say I'm on the fringes and not
>actually supported, and even although I get all the other muxes well enough
for a
>stable picture they won't offer a site visit (ariel upgrade for Ł40). I
can't watch
>any music channels (MTV or UK-PLAY) as they're on muxes C and D, and
there's too
>much mosaic or just a red dot.
>
>So... I tried to upgrade myself, starting with a newer and better
distribution
>amplifier as the old one is a bit suspect.
>
>Using the OnD signal strength indicator for measurement; I used to get 2.4
for
>1,2,A,B and 1.8 for C,D.
>
>My aerial setup is (as bought with the house) :-
>
>An aerial pointing at Crystal Palace
>A smaller aerial pointing at Hannington